Writing in the Journal of Public Health, researchers from Masaryk University in the Czech Republic analyzed data from the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC), initiated by the World Health Organization for Europe in 1985 and coordinated by Bristol University.
“This study is the first large-scale study that looked at this association in Central European populations and strengthened present findings emphasizing the importance of vitamin B12 intake during [the] prenatal period, particularly at the time when dietary patterns prioritizing plant sources were becoming more popular,” the researchers wrote.
Vitamin B12, found primarily in animal-based foods like meat, eggs and dairy, plays a pivotal role in the formation of red blood cells, neurological function and DNA synthesis.
Importance of B12 during pregnancy
A deficiency in vitamin B12 during pregnancy—particularly common in women who follow vegan or vegetarian diets or have malabsorption issues—can lead to health complications ranging from maternal fatigue to neural tube defects at birth in severe cases.
As an essential nutrient, it is needed for intrauterine fetal development (particularly for the nervous system during childhood), contributes to axon myelination (essential for impulse conduction from cell to cell) and protects neurons from degeneration. It also supports brain growth, neurogenesis and synaptic connectivity, especially in the auditory and visual cortices.
“Disruptions in myelination can significantly impact central nervous system function later in childhood, resulting in slower conduction in the auditory and visual systems, which can interfere with learning and social interactions,” the researchers explained. “Additionally, vitamin B12 is active in the metabolism of both fatty acids and amino acids and is a required cofactor in one-carbon metabolism; its deficiency leads to elevated levels of homocysteine.”
These higher homocysteine concentrations during pregnancy could in turn affect a child’s expressive language and gross motor abilities.
Study details
The study examined associations between prenatal vitamin B12 intake and children’s cognitive development in a group of 5151 pregnant women with expected delivery between March 1, 1991 and June 30, 1992.
Parents filled out health, lifestyle, dietary habit, demographic, psychosocial factor and environmental exposure questionnaires about themselves and reported on their child’s speech and language development at 18 months and 3, 5 and 7 years. The researchers also measured Intelligence quotient (IQ) at eight years in subsample of 854 children.
Children of mothers with prenatal vitamin B12 intake over 3.0 μg/day demonstrated higher language, speech and understanding scores. Higher intakes were also associated with better verbal IQ.
“While we did not find significant associations with total IQ […], it is noteworthy that the effect of vitamin B12 remained evident specifically in the verbal subtest, maintaining a consistent trend from 18 months onwards,” the study noted.
“Language development is a fundamental aspect of cognitive growth, serving both as a key of communication and a critical tool for learning and social interaction. Research has shown that early language skills significantly shape broader cognitive abilities and are strong predictors of later academic success and social integration.”
Given the mixed results in the science to date, the researchers called for future studies to explore the mechanisms underlying their observed association and to investigate the optimal dose of vitamin B12 supplementation during pregnancy, as well as the effects of supplementation on other health outcomes.
“Our categorical analysis indicates that the fourth quartile, which approached the recommended dietary reference values set by the European Food Safety Authority (4.5 μ/g), supports the notion that increasing vitamin B12 intake may be beneficial,” they added.
In the United States, the current recommended daily allowance for pregnant women is 2.6 micrograms (μ/g) per day.
Source: Journal of Public Health
doi: 10.1093/pubmed/fdae307
“Vitamin B12 intake during pregnancy linked to child speech development and intelligence quotient”
Authors: Eliska Hrezova et al.
